It measures 352 feet long, weighs 300 pounds and takes three men to slide. Skip Solberg and Jay Francis said it will calculate to "six significant digits," which apparently is a good thing. Some other engineers smiled and nodded when hearing of the "significant digits."

Solberg, 51, of Arlington, and Francis, 53, of Richardson, said it was important to them that theirs be a working slide rule. They said they weren't sure if the previous world- record holder -- a 323-footer built 22 years ago at the University of Illinois -- was a working model.

In any case, they wanted theirs to work. It's an engineering thing. A source of pride, too.